Swift3でボタンを揺らす簡単なサンプル

IBOutletで接続

@IBOutlet weak var Button: UIButton!

viewDidLoad() 内で実行

UIView.animate(withDuration: 0.6,
                       animations: {
                        self.Button.transform = CGAffineTransform(scaleX: 0.6, y: 0.6)
        },
                       completion: { _ in
                        UIView.animate(withDuration: 0.6) {
                            self.Button.transform = CGAffineTransform.identity
                        }
        })

参考

Scale UIButton Animation- Swift

Swift3でボタンを揺らす簡単なサンプル